GeigerGPX is an Android application designed to simultaneously record GPS tracks and dose-rate data from a Geiger counter.
Currently, RADEX RD1008 (РАДЭКС РД1008) and RADEX RD1224Si are supported.
No hardware modifications are required; the app records signals directly via the microphone (an external wired microphone is recommended). To use the app, simply enable audio output on your device:
- RD1008: Switch to "search" mode, set the threshold to zero, and turn on the sound.
- RD1224Si: Enable "quantum sound."
- Audio pulse detection: Utilizes three Goertzel filters (tuned to 3276.8 Hz for the RD1008, plus two witness filters) alongside a pulse duration filter for accurate detection.
- GPS & dose recording: Records your geographic position and overlays dose-rate data onto the track timeline.
- GPX export: Saves tracks in GPX format with custom extensions for dose-rate data. (Standard GPX viewers will display the path but not the dose information.)
- Dose-aware mapping: Visualize recorded tracks on a map using color-graded lines or generate heat maps from multiple tracks.
- Real-time dose rate preview: Displays a fast, real-time dose rate estimate based on the last 10 detected pulses.
- Confidence interval calculation: Automatically calculates confidence intervals (CIs) using χ² quantiles at a 95% confidence level.
- Long-term measurement mode: Useful for long-duration sampling in low-background environments.
- Measurement results export: Saves detailed measurement results to a separate GPX file using tags that include descriptions, coordinates, timestamps, dose rates, and CI data.
- Dose rate plots: View dose rate plots for recorded tracks with adjustable averaging windows (fixed-duration or Epanechnikov kernel estimator).
- Track editing: Crop the start or end of a track, split tracks, or flag specific points as "bad" to exclude them from map visualizations.
- Bluetooth audio (experimental): Supports audio capture via Bluetooth headsets, though stability and quality are currently lower than wired or built-in microphone input.
Note: At high dose rates, the dosimeter may not audibly emit every pulse, so phone-side estimates can be biased low.
Open gpx-rad-extension-specification.html in a browser for the draft rad extension specification for GPX, organized by metadata, track points, and waypoints. It includes tag meanings, units, serialization details, and highlighted GPX usage examples. The page is a single self-contained file and works offline.
